Z80em and 6502em

Matt Thompson

The emulation of old computer platforms and the playing of old computer games is very much "in" at the moment, so to follow on nicely from last months look at Commodore emulation on RISC OS here we have new and improved versions of two more 8bit computer emulators. They are !Z80em which emulates the ZX Spectrum and !6502em which emulates the BBC Micro. These new versions include a number of updates, the most important being that they both run natively on the Iyonix.

Both emulators were originally published by Warm Silence Software but the author Michael Borcherds has released these new updated versions himself and are available from his website which can be found at www.borcherds.co.uk/murklesoft/riscos.

!Z80em (V4.00)

The ZX Spectrum start up screen

!Z80em is easy to run, simply install it on the hard-disc and then when it is run it will install itself onto the iconbar. Clicking on the icon will bring up the emulator window, and clicking the menu mouse button on the icon will bring up a menu. Selecting the choices option will bring up the !Z80em configuration options, as shown below.

The !Z80em Configuration window

Amongst the options you can select whether the emulator is in 48K mode or 128K mode, the speed of the emulator, sound on/off and whether the emulator will run in the desktop or in single task mode.

Playing Games on !Z80em

Loading games into !Z80em is very simple indeed. Several different filetypes are used to store Spectrum games, these include Z80, TAP and TZX. If a file has a Z80 filetype then simply double click on it and the game will run straight away. Don't forget that if the game is for a Spectrum 128K then you need to make sure the emulator isn't in 48K mode and vice versa. The icon on the icon bar will indicate what mode is currently set. The other filetypes TAP and TZX are a bit different but easy to load; simply double click on the file and then from the main emulator screen, where it says (C) 1982 Sinclair Research, in 128K mode press return when the light blue bar has highlighted Tape Loader. Type LOAD "" or press J and ALT/P twice, press RETURN and the game will 'load' and then can be played.

When you get a TAP file running it is worth returning to the program menu and selecting 'Save', then save the Z80 snapshot. You can then simply double-click the file to run the game instantly in future. You can also do this by clicking 'Menu' over the main emulator screen and from here you can also make a screengrab of the current screen and save it as a spritefile. The TZX filetypes are loaded into !Z80em in the same way as TAP files and should work OK, but TAP files seem to be the most common filetype from my experience.

!Z80em is a very good emulation of the ZX Spectrum and plays the games well. It is responsive and the sound and graphics behave in exactly the same way the they did all those years ago. I tried many games with !Z80em and every one has worked fine.

!6502em (V4.00)

The BBC Micro start up screen

The BBC ROMS are not supplied with !6502em for copyright reasons. To use !6502em you will need to use the supplied program !Rip65host to extract them from !65host. This will then let you emulate a BBC Model B. To emulate the BBC Master, Master Compact or the Acorn Electron you will the ROMS for these machines.

Once the ROM(s) are in place !6502em is loaded in the same way as !Z80em, and the icon will appear on the icon bar. Clicking the Menu button over the icon will bring up the menu. From here you can see which ROMS are currently installed and you can make screengrabs of BBC screens using the 'Sprite' option. There are other options as well, and by clicking on 'Config' the following panel will be displayed :

The !6502em Configuration window

From here you can select which machine you want to emulate (subject to ROMs) the speed, sound, keymaps and other options. By clicking the mouse on the icon a very familiar screen (and noise) from the past will appear. MODE 7 is very well emulated and displays as it used to on the BBC machines.

Running games on !6502em is different to !Z80em. It's not just a double click, you have to set them up to run, but it's not difficult to do.

When you download a BBC game from the internet (such as the Stairway to Hell site) it will be in an archive which will contain a single file in data format. To get it into a usable format you now need to load the application !BeebArc which is supplied with !6502em. Once this is installed on the iconbar simply drag the game data file to the icon. A box will now pop up, and simply drag this to the destination directory. Now click on this new directory and it will be full of files. Some will be datafiles and others will be BASIC files. If there is a file called !Boot then double clicking on that (with !6502em loaded) should run the game. You can also get the game to run by dragging a BASIC file to the !6502em icon. The appropriate BASIC file is normally called "Loader" or "Load" or something similar. When the game has been successfully loaded into !6502em it is worth creating a BBC snapshot from the 'Save' option so that next time you run the game you can just double click on this file and instantly load it.

!6502em plays the BBC games very well, both the sounds and graphics are emulated very well and act as they would have on the BBC. I have tried many games on !6502em and the vast majority work perfectly. There were some that didn't work but hopefully will in the future.

Game Galleries

Below is a selection of games running on both !Z80em and !6502em as the emulators display them.

ZX Spectrum

Chuckie Egg

Fred

Jet Set Willy 2

Mikie

Scuba Dive

Trap Door

BBC Micro

Citadel

Frak

Matchday

Thunderstruck

Vindaloo

MrEE

Where to get games.

Games are available to download from the internet. A good resource for ZX Spectrum games is the World of Spectrum at www.worldofspectrum.org which has a massive selection of Spectrum games. Just about every Spectrum game is available here. If you don't want to download them then there a number of commercial collections available

You can get BBC games from The BBC Lives at http://bbc.nvg.org and also Stairway to Hell at www.stairwaytohell.com. There are also Electron games on this site, but I haven't seen any commercial collections of BBC games. There are also brand new BBC and ZX Spectrum releases which should work with the emulators without any problems. Check Cronosoft at http://www.cronosoft.co.uk.

Lost BBC Games

I had a really good look on the Stairway to Hell website as I haven't seen it before and I was pleasantly surprised to find in the Lost and Found BBC games section some of the games I remember reading about but which never happened, such as Daxis (found demo) and Bolo (lost). Some are lost but some have been found and I was amazed to find all those years ago that Ultimate did actually write Cookie for the BBC but never released it, I used to play it on friend's ZX Spectrums and wished it was available for the BBC and all this time it was!

Cookie

Another surprise was to find that Bubble Bobble also existed for the BBC Micro but never got released. This is a brilliant game, and although since this version was written there have been better releases it's great to see such an arcade classic being run on the good old BBC.

Summing up then, these are two excellent emulators, which recreate the ZX Spectrum & BBC Micro very well indeed. These new versions have many improvements, the most important being Iyonix compatibility, and I would recommend them to anyone who is interested in emulation and the playing of classic games.